Help me understand low phosphates regarding Cyano Bacteria

[RobB'z Reef]

I’ll testify for Brandon’s advice. A full cleaning and new water never killed any of my fish or corals. My tank looks better with every rip clean I do.

I second this, I was doing it back in early 2k before any of these forums were a thing.

 

[Dan_P]

Surprised that this is not very known because when I heard about it was already in the 80:ties - just before the discussion about nitrate as a growth limiter in sea water was introduced. A large chemical firm had developed a method to be rid of H2S in sewage systems (one of the larger treat to the health for sewage workers) and try to have this method accepted (and sold) to many municipalities. The method was simple - just add NO3 into the sewage. Unlucky for them (at least in Sweden) short afterwards the alarm of NO3 induced eutrophication in seawater came

The first explanation that I heard was the the electron acceptor explanation - oxygen -> nitrate -> sulphur compounds-> carbon dioxide but it shows up that it was mostly other organism than the oxygen - nitrate group that was responsible for the H2S production. There was no super bacteria that could swing between oxygen, nitrate and sulphur compounds as electron acceptor. (however - lately - the discovery of non-sulphur purple photosynthetic bacteria have shown that it exist ) - maybe its time to relearn again

I have to admit that I have not dig in further in the literature recently because this knowledge have been as the law of gravity for me - self-evident I have missed the nitrite explanation - however I have not put this together with only DNRAs and if the nitrite theory is true - it must be valid for both the classic denitrification and maybe even the sulphur driven autotrophic denitrification - both processes know for producing nitrite as intermediate stage. However I have some doubt because I have seen occasions with both nitrite and H2S in the water. But I leave it to you for deeper digging And nitrite is necessary in the anammox process - the process that convert NH3/NH4 directly into N2

However - nitrate in the water suppress H2S production - and it has been my dogma for many years when I have advocated for readable NO3 concentrations in our aquaria > 2 ppm. And that´s the reason why I use NO3 in the fight against cyanobacteria. I know it works but that is because lack of usable nitrogen for other organisms I do not buy - NH3/NH4 use to be common together with cyanobacteria when they use their toolbox of different ways for nitrogen fixation. The explanation for NO3 effectiveness in this situation must be an other and this theory (H2S production suppressor) have been the best fitted for me to now. But I´m no microbiologist - only a very interested hobbyist that have many strings on his lyre ( a translated swedish expression for a multi-tasker)

Sincerely Lasse

I was just thinking about the conditions required to grow thick mats of cyanobacteria outside the aquarium in salt water in an illuminated petri dishe: organic particulate matter (e.g., dry fish food or glutamine (I did not try all amino acids). I never had good luck with inorganic nitrogen, which I cannot explain. Neither ammonium chloride nor nitrate stimulated growth. Even stranger, my cyanobacteria died (!!!) if I only supplied nitrate nitrogen. Clearly, there is more to this story that needs lab work to understand It.

The other lesson learned came from observing @taricha results on cyanobacteria growth: different mat forming species behave differently with regards to what is needed to achieve thick mat growth. He was growing the red species that is common in reef aquarium while I was growing several species obtained from Long Island Sound. When we finally figured out how to ship the red species, both @taricha and @Rick Mathew had made valiant attempts, none of my successful seawater media for my cyanobacteria would stimulate the red species to grow mats.

I offer these observations to demonstrate that understanding what makes microorganism grow dense mats in aquarium is not simple AND that the species can determine the success of a control strategy, which is usually stated as “every aquarium is different” when tried and true methods fail.

Continued good luck controlling cyanobacteria!

Dan

 

[Lasse]

Even stranger, my cyanobacteria died (!!!) if I only supplied nitrate nitrogen

And ...... that´s exactly the goal when I add nitrate - to make that the Cyanobacteria not get P from the substrate.

none of my successful seawater media for my cyanobacteria would stimulate the red species to grow mats.

Without knowing your media I can´t say bu or ba

Sincerely Lasse

 

[Dan_P]

Without knowing your media I can´t say bu or ba

An example: Instant Ocean, 1 ppm PO4, 100 ppm glutamine. 0.2 ppm Iron

 

[Lasse]

When the argue about high dissolved inorganic nutrition as a trigger disappear. Glutamine is an organic N- source that can pass through the cell walls of one cells organisms at least . I suppose that your cyanobacteria was alive in the solution - but just no mats formed.

Sincerely Lasse

 

[Dan_P]

When the argue about high dissolved inorganic nutrition as a trigger disappear. Glutamine is an organic N- source that can pass through the cell walls of one cells organisms at least . I suppose that your cyanobacteria was alive in the solution - but just no mats formed.

Sincerely Lasse

The cyanobacteria did indeed die. The filaments started to appear kinked and no longer moved. Then the filaments fragmented into individuals cells and then the entire organism appeared to melt. This is very different from filaments that just lengthened slowly. Mat forming occurred when there was continuous accumulation of long filaments.

The notion of a trigger might be incorrect. When there was plenty of the right kind of nitrogen and phosphorous available, mats formed. Ratios didn’t seem to matter to growth or mat formation. If the cyanobacteria was starved of a nutrient, no mats formed, and apparently no nitrogen fixing to correct the nitrogen deficit for the organisms studied.

With these observations in mind, I propose that simply making phosphorous available is not enough to create cyanobacteria mats, though if you can starve it of phosphorous a mat cannot form. To create a large amount of biomass like a cyanobacteria mat also requires a large supply of nitrogen and large removal rate of oxygen.

 

[Lasse]

When there was plenty of the right kind of nitrogen and phosphorous available, mats formed.

You write that you had 1 ppm PO4 in the water column and no mat formation before. Did you get mat formation with 1 ppm in the water column and organic matter in the discs?

Sincerely Lasse

 

[Dan_P]

You write that you had 1 ppm PO4 in the water column and no mat formation before. Did you get mat formation with 1 ppm in the water column and organic matter in the discs?

Sincerely Lasse

The only time that I had mat formation was with PO4+organic nitrogen. You should know that experiments were not performed with pure cyanobacteria (never my intention).

These were not pure cyanobacteria cultures but culture medium inoculated with cyanobacteria harvested from the aquarium, rinsed, and vigorously shaken to suspend the broken filaments to ensure only tiny pieces of filaments and not little mats were added to the medium. There is no doubt that bacteria came along for the ride. And these bacteria might very well have been what needed the organic nitrogen to make organic amines and amino acids that fed the cyanobacteria. They also likely supplied CO2 and removed O2. When the medium contained only inorganic nitrogen, the inoculum did not grow well. You might expect this to be the case if the heterotrophic bacteria partners needed carbon to grow and feed the cyanobacteria. These observations do not prove anything. What they point to is that the cyanobacteria I was trying to grow do not form mats without organic nitrogen, even with a 1 ppm PO4, 100-300 ppm of nitrate and 0.2 ppm iron. Even ammonium chloride failed to stimulate mat formation or even strong growth. A seemingly complicated situation to explain.

 

[Lasse]

What was the organic nitrogen?

Sincerely Lasse

 

[Dan_P]

What was the organic nitrogen?

Sincerely Lasse

I used glutamine, glutamic acid and arginine. @taricha used things like fish flakes.

 

[Lasse]

Thank you for the answer.

I´ll stop arguing here - too much off topic I suppose. I will prepare an own thread because the last post from you did not through my thinking overboard - it strengthen them with some adjustments. However if @Snoopdog think it is in topic in this thread - I will continue with my long answers to you that will result in a long answer from you and so on

Sincerely Lasse

 

[Snoopdog]

Thank you for the answer.

I´ll stop arguing here - too much off topic I suppose. I will prepare an own thread because the last post from you did not through my thinking overboard - it strengthen them with some adjustments. However if @Snoopdog think it is in topic in this thread - I will continue with my long answers to you that will result in a long answer from you and so on

Sincerely Lasse

Some of the post are above my head, but I am reading them trying to completely understand the chemistry of it all.

 

[Lasse]

I will prepare my answer to @Dan_P - Please let me know when you think I go bananas - do not want to crash your thread.

Sincerely Lasse

 

[Snoopdog]

I will prepare my answer to @Dan_P - Please let me know when you think I go bananas - do not want to crash your thread.

Sincerely Lasse

No, it is fine. If anything the back and forth is good reading material. One day I may understand everything regarding water chemistry as you guys do.

 

[Lasse]

We do not understand - we only sounds like we do

Sincerely Lasse

 

[taricha]

The organic N sources that @Dan_P and I used - at the surface not all that similar - Glutamine for Dan, mix of crushed fish flake and freeze dried phyto for me. However the breakdown of both of these involve consistent, gradual ammonia release.
Can't say what part of the cyano / heterotrophic bacteria consortium consumed what out of the organic / inorganic mix - but it's possible that the ammonia also played a role. Or maybe everything preferred the proteins/aminos better and the ammonia just built up over time.

 

[Dan_P]

Thank you for the answer.

I´ll stop arguing here - too much off topic I suppose. I will prepare an own thread because the last post from you did not through my thinking overboard - it strengthen them with some adjustments. However if @Snoopdog think it is in topic in this thread - I will continue with my long answers to you that will result in a long answer from you and so on

Sincerely Lasse

Looking forwards to your refined ideas and hopefully some ideas on how to experimentally test them! Dan

 

[Snoopdog]

I must have been bad in explaining my thoughts. I do not see it primary as a competition for nutrients in the water.

My theory in short

According to mat building cyanobacteria - they are always present but not always form mats. I think that the critical point is when they decide to build mats or with other words take some of the energy from the photosynthesis and excrete a slime of mostly carbohydrates. My idea is that when they can catch PO4 from the water column - they do that and they have some competition some algae and fungus about available space. They stay put. If the PO4 will be sparse or nonexistent - they need to get PO4 from other sources. On way of doing this is to form a mat that create anaerobic environment between the mat and substrate. In this anaerobic environment bacteria will grow - both Nitrogen fixating bacteria, denitrifikation bacteria and when the NO3 is zero or very low - bacteria that produce hydrogen sulphide will establish themselves. The hydrogen sulphide will break the bounds between different metals and phosphate in the substrate and phosphate will be released to the hungry cyanobacteria. If the area they establish themself content a high amount of organic matter - PO4 will be released from the organic matter too. When the trigger had started the mat forming - it becomes a self playing piano between the mat and the substrate - first when all P has gone - the mat start to decline.

According to nitrate - I not only concentrate me on that because it is a inorganic nitrogen source - there is plenty of other sources of inorganic N and even some organic N (amino acids) that unicellular organism can use both in a autotrophic and an heterotopic way (primary and secondary producers). I´m interested of NO3 because it has another important role in anaerobic bacterial community. As long NO3 exist in the water - it block most of the hydrogen sulphide producers, hence the release of PO4 from metal-PO4 compounds in the substrate.

I do believe that low PO4 can be a trigger for mat forming but also low NO3 can act that way too. Probably there is other triggers too. I also believe that there can be part of the tank there it can microenvironment with low PO4 or NO3 - especially in tanks with low flow or dead spots.

Because I see the mat forming as the Gordian knot - I use three actions when the mats has establish themselves. Disturb the mats as much as possible, have enough high NO3 levels in order to have zero hydrogen sulphide production below the mats and if PO4 is low - have a PO4 concentration between 0.05 to 0.1 mg/L. Good circulation (I love standing waves) in order to not establish favorable microenvironment can help too

I agree that this is only a theory and do not need to be the truth. However - the theory have helped me to stand free from Cyanobacteria mat forming for most of the time and with a treatment schema when things goes downhill. The schema include disturbing of the mats, keep up PO4 to 0.05 - 0.1, rise the NO3 up to at least 5 ppm and sometimes go down in light intensity and slowly rise it back to normal during a couple of weeks. The lowering of the light aim to lower the secret (slime) production (they need photosynthesis for that).

I prefer to work with the biology instead of nuking it.

Sincerely Lasse

I reread this and it makes a lot of sense now. Another thing I notice is the choice location the mats form. They seem to form more on my dead rock than the live rock, almost non-existent on the live rock. It also forms in the sand but really only where light is directly hitting, basically using the light as food. Disturbing the formation definitely seems to be helping on a day to day basis. I have been trying to test PO4 daily to make sure to keep it elevated, something is eating the PO4 rather quickly. I also have been blowing the rocks off daily.

 

[Lasse]

Looking forwards to your refined ideas and hopefully some ideas on how to experimentally test them! Dan

Here it comes but this is ecology and it is not easy to test as a cause - effect in a petri dish. But can you repeat tests with the common used Guillard's F/2 nutrient media solution and if that not work as an mat forming agent - just add amino acids. I would first test with a solution like F/2 but without the vitamins. Next step - if nothing happens - ad the vitamins - and still no mat forming - ad some amino acids. Formula for F/2 - here You can by it too - seek for F/2 media

IMO fIf you can show that amino acids are essential for nitrogen uptake among mat building cyanobacteria - it would be a breakthrough. In my thought below I have assumed that

Your findings - if you are able to repeat them - corresponds with reports saying that adding amino acids sometimes can trigg cyanobacteria outbreak - but there is also outbreak in aquariums without adding amino acids - in fact it is very common in newly started aquariums without any internal production of amino acids. However - amino acids is a commonly used additive for low nutrient systems and probably common in poorly skimmed systems. Amino acids is the building blocks for proteins. Amino acids is an interesting organic nitrogen compound because it have been shown that the uptake of it in single cells are faster than the uptake of NH3/NH4. Cyanobacteria are either unicellular organisms or consist of a single cell layer with the cells in a row. Most micro algae is alike in cell construction including dinoflagellates. Your findings indicate that these benthic cyanobacteria can use amino acids and inorganic PO4 in the water column. So can microalgae too and if amino acids are an essential nitrogen source for cyanobacteria (you tests indicate that) it will not overturn my theory - instead it strengthens the theory in a complex ecosystem. However - I have to go back one or two steps and reinstall competition of space as an factor

In a ecosystem - benthic organisms compete for food and space and if different organism have the same demands - the speed of growth will decide which organism that will dominate. If food is there - the fight for space is the most important issue, hence growth speed have an enormous importance

For me - it's clear that normal microalgae have a faster growth than mat building cyanobacteria when all demands are satisfied. If we look at the two main combatants - cyanobacteria and microalgae I think that we can look at this first

1. Both can use free inorganic P (as PO4)
2. Cyanobacteria have a possibility to use PO4 produced by anaerobic bacteria below the mats either from metal bounded PO4 (with help of H2S) or through bacterial mineralization of organic matter. Microalgae in general can´t that with exception of dinoflagellates that can "dive" into the bottom substrate and pick up produced PO4. Maybe some other mobile microalgae can this too.
3. Your experiments indicate that mat forming benthic cyanobacteria prefer amino acids (or maybe demand) as nitrogen source.
4. Microalgae can use amino acids but also NH3/NH4 and for many of them NO3 too.
5. In a given situation all of these nitrogen sources is evenly spread and will be used on an equal basis of each type of organisms - the amount of individuals of the different organisms will decide the use of it and how much space that it is occupied of each organism involved.

Enhanced theory for triggers that induce mat forming if amino acids is cyanobacterias prefered nitrogen source.

This is only free fantasies - it could be this way, it could be partly this way or it can total opposite to this way - but I hope this will stimulate the discussion

PO4 > 0.03 mg/l; all nitrogen sources constant above 0.4 mg/L as N

No change in competition

PO4 -> 0.03; Inorganic N sources constant; concentration of amino acid rise

As long as it is not to much rise of amino acids - no change in competition

PO4 -> 0; all nitrogen sources constant

Microalgae will have difficulties with growth - grow rate decline - their use of amino acids as nitrogen source decline. Result - more space and amino acids for the cyanobacteria will result in mat forming and suddenly they have free access to both PO4 and amino acids. PO4 rich environment will be occupied first (areas with organic matter and other stored PO4 sources - including newly dead coral tissue)

PO4 ->0; Inorganic N sources constant; concentration of amino acid rise

Speeding up the above process

PO4 steady above 0.03 mg/L Amino acid constant - inorganic nitrogen sources ->0

Microalgae will have difficulties with growth - grow rate decline - their use of amino acids as nitrogen source decline. Result - more space and amino acids for the cyanobacteria will result in mat forming and suddenly they have free access to both PO4 and amino acids. Amino rich environment will be occupied first (areas with organic matter - including newly dead coral tissue)

PO4 steady above 0.03 mg/L Amino acid rising - inorganic nitrogen sources ->0

Speeding up the above process

PO4 -> 0; amino acids constant or rising; Inorganic Nitrogen -> 0

Catastrophe

This is a try to explain the start of the problem. IMO – keeping a PO4 concentration above 0.03 – 0.05 mg/L, keeping inorganic nitrogen NH3/NH4 and/or NO3 above certain levels (NO3) or keep a flux of it (NH3/NH4) through the system and as low levels of amino acids as possible will prevent most cyanobacteria outbreaks in a large scale. However small outbreak on dead coral tissues or other organic concentrated waste can always happens.

How to act when an outbreak has happened.

Local outbreak

I normally just take a toothbrush and brush away the cyanobacteria from dead corals or just brush away organic matter. Check my nutrient levels

Heavy outbreak

Because of heavy outbreak normally spreads all over – it is – IMO – important too add NO3 (hinder H2S formation below the mats) and disturb the mats as much as possible. PO4 concentration above 0.05 and NO3 between 5-10 mg/L. If possible – lower the light intensity and let it slowly rise up too normal levels during 2 – 3 weeks. Stop all amino acid additions.

This trick have worked for me for many years and I know a lot of people that handle the problem the same way

Sincerely Lasse

 

[Randy Holmes-Farley]

I second this, I was doing it back in early 2k before any of these forums were a thing.

Reef forums were a thing even in the 1990's. I was a moderator on Compuserve Fishnet.